This invention relates to conveyor apparatus used to move articles along a predetermined path and rotate each article 90.degree. about a vertical axis such that another side thereof is leading. Frequently such articles as cartons of packaged or frozen food must be rotated for purposes of applying wrappers, identification, et cetera. The rotation of such articles must be achieved in a precise and efficient manner so as not to slow the travel of the articles more than necessary while still assuring that rotation is actually achieved. Naturally if rotation is not achieved, subsequent processing of the article is impossible or ineffective and can result in stoppages of the total conveyor line. It is therefore the object of this invention to provide an efficient and relatively simple apparatus for conveying and rotating articles.